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DNA damage, photorepair, and survival in fish and human cells exposed to UV radiation
Author(s) -
Ahmed Farid E.,
Setlow Richard B.,
Grist Eleanor,
Setlow Neva
Publication year - 1993
Publication title -
environmental and molecular mutagenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1
H-Index - 87
eISSN - 1098-2280
pISSN - 0893-6692
DOI - 10.1002/em.2850220105
Subject(s) - dna damage , biology , fish <actinopterygii> , dna repair , dna , mutagen , genetics , toxicology , fishery
The effect of various wavelengths of UVB radiation on the induction of cyclobutane pyrimidine dimers in fish cells and human fibroblasts and the repair of these lesions were studied using an UV‐endonuclease to measure dimers (endonuclease sensitive sites) by sedimentation of radioactive DNA, by gel electrophoresis of unlabeled DNA, and by cell survival. The data show that fish cells have an efficient photoreactivation system at wavelength > 304 nm that reverses cytotoxicity and dimer formation after exposure to filtered sunlamp irradiation of a shorter wave‐length (λ > 290 nm). Shorter wavelengths in UVB (<304 nm) are more effective in photoreversal than longer ones (<320 nm). As a consequence, 50–85% of dimers induced by these wavelengths in fish are photoreactivated while they are being formed. A major cytotoxicological lesion is the cyclobutane pyrimidine dimers. Cultured human fibroblasts do not possess such a repair system. These results indicate that sun‐lamp irradiation has wavelengths that both damage and repair DNA.